Reaction‐Induced Reversible Reconstruction Enhanced Ni‐MgO/CaO Dual Functional Material for Stable CO ₂ Capture and In Situ Conversion

ABSTRACT Calcium looping dry reforming of methane (CaLDRM), which realizes CO ₂ capture and in situ conversion to valuable syngas, presents a promising route for large‐scale CO ₂ fixation. However, its development is hindered by the scarcity of efficient and durable dual‐functional materials (DFMs) that combine high capture capacity with stable catalytic activity. Herein, we construct a Ni‐MgO/CaO DFM by engineering NiO‐MgO solid solution (Mg _x Ni _1‐x O) on a hierarchically porous CaO support incorporating highly dispersed MgO. The modulated Mg _x Ni _1‐x O phase fosters a strong metal‐support interaction to inhibit Ni agglomeration and carbon deposition, and simultaneously acts as a structural stabilizer to mitigate CaO sintering. The resultant material delivers a CO ₂ uptake of 11.5 mmol g ⁻¹ , an in situ CO ₂ conversion of 90 %, and a syngas yield of 55 mmol g ⁻¹ at a relatively low temperature of 620°C, while exhibiting insignificant deactivation over 65 cycles, outperforming the previously developed CaO‐Ni based DFMs. Mechanistic studies reveal that this material achieves a reaction‐induced reversible reconstruction during the CaLDRM process, which not only sustains the Mg _x Ni _1‐x O‐mediated structural stability enhancement but also ensures the high accessibility of catalytic sites, thereby decoupling the activity‐stability trade‐off. This work provides a practical material design strategy for efficient CO ₂ capture and catalytic conversion processes.